/*
 * ProGuard -- shrinking, optimization, obfuscation, and preverification of Java bytecode.
 *
 * Copyright (c) 2002-2018 GuardSquare NV
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this program; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package proguard.classfile.editor;

import proguard.classfile.*;
import proguard.classfile.constant.*;
import proguard.classfile.constant.visitor.ConstantVisitor;
import proguard.classfile.util.SimplifiedVisitor;

/**
 * This ConstantVisitor remaps all possible indices of bootstrap methods of the constants that it visits, based on a
 * given index map.
 *
 * @author Eric Lafortune
 */
public class BootstrapMethodRemapper extends SimplifiedVisitor implements ConstantVisitor {
    private int[] bootstrapMethodIndexMap;

    // Ignore (skip) lingering InvokeDynamic constants that
    // refer to removed bootstrap methods.
    private final boolean ignoreDanglingConstants;

    public BootstrapMethodRemapper() {
        this(false);
    }

    public BootstrapMethodRemapper(boolean ignoreDanglingConstants) {
        this.ignoreDanglingConstants = ignoreDanglingConstants;
    }

    /**
     * Sets the given mapping of old constant pool entry indexes to their new indexes.
     */
    public void setBootstrapMethodIndexMap(int[] bootstrapMethodIndexMap) {
        this.bootstrapMethodIndexMap = bootstrapMethodIndexMap;
    }

    // Implementations for ConstantVisitor.

    public void visitAnyConstant(Clazz clazz, Constant constant) {}

    public void visitInvokeDynamicConstant(Clazz clazz, InvokeDynamicConstant invokeDynamicConstant) {
        invokeDynamicConstant.u2bootstrapMethodAttributeIndex =
            remapConstantIndex(invokeDynamicConstant.u2bootstrapMethodAttributeIndex);
    }

    // Small utility methods.

    /**
     * Returns the latest bootstrap method index of the entry at the given index.
     */
    private int remapConstantIndex(int constantIndex) {
        int remappedConstantIndex = bootstrapMethodIndexMap[constantIndex];
        if (remappedConstantIndex < 0) {
            if (ignoreDanglingConstants) {
                return constantIndex;
            } else {
                throw new IllegalArgumentException("Can't remap bootstrap method index [" + constantIndex + "]");
            }
        }

        return remappedConstantIndex;
    }
}
